• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.541-548
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• 2023

Behavior serves as an important indicator of the effects of environmental stressors on organisms. In this study, one-year-old abalone Haliotis discus hannai (15.1±0.8 mm) were used and each 0.34 m2 tank was stocked with 100, 150, 200, 250, and 300 juvenile abalone. After 328 days, we found that the low stocking density treatment showed significantly higher growth, whereas the high stocking density treatment showed significantly lower growth. In addition, abalone showed a lower rate of movement, distance moved, and velocity at higher stocking densities, but only velocity differed significantly. In contrast, In the Supplied the feed tanks significant difference between the moving distance and velocity. When the two groups of different sizes were mixed in tank, the rate of movement, distance moned, and velocity showed significant differences between differently-sized indivisuals. Our study indicates that breeding abalone at high densities has a negative effect on their growth and survival, which is thought to primarily be caused by spatial competition, and secondarily by differences in body size, ultimately affecting growth and productivity.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.225-232
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• 2013

This study looked into recovery rate and histological changes in the gills of juvenile abalone Haliotis discus hannai by exposure time (3, 6, 12, 24 and 48 h) of different water temperatures (15, 20 and $25^{\circ}C$) and salinities (30, 25, 20 and 15 psu) to understand reasons for the death of abalone exposed by low salinity water. In each water temperature, abalone spats that were exposed to low salinity water (less than 20 psu) for over 6 hours showed decrease in survival rate during recovery and those were exposed at the salinity of 15 psu for more than 24 hours all died. Histological observation showed expansion or damage of gills of the species which were exposed at less than 20 psu for over 6 hours. In case of abalones exposed at the salinity of 15 psu for over 24 hours, most gill tissues were destroyed. This result was glaringly obvious at a higher water temperature, lower salinity and longer exposure time. Accordingly, suffocation caused by damage of gills considered one of direct causes of the death.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.217-225
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• 2007

This study was conducted to estimate the general genetic parameters, heritabilities, and genetic and phenotypic correlations on growth-related traits by studying multiple trait animal model in two Korean abalone species, Haliotis discus hannai and H. discus discus. The data was collected from the records of 3,795 individuals produced from 54 sires and 74 dams in Haliotis discus hannai and 399 individuals produced from 7 sires and 7 dams in Haliotis discus discus. The data was evaluated by the Genetics and Breeding Research Center, National Fisheries Research & Development Institute (NFRDI). Genetic parameters were estimated for two abalone species raised in Bukjeju branch, NFRDI, from May 20 to November 1, 2004. The heritability estimates for growth traits of shell length, shell width and body weight obtained from restricted maximum likelihood (REML) were ranging from 0.73 to 0.78 in Haliotis discus hannai, and from 0.87 to 0.89 in H. discus discus. The heritabilities for shell shape and condition factor were ranging from 0.17 to 0.20 in Haliotis discus hannai, and from 0.01 to 0.45 in H. discus discus. Genetic and phenotypic correlations were over than 0.96 between shell parameters and weight in both of abalone subspecies, indicating that breeding for weight gains could successfully be achieved by selecting for shell length.

• Journal of Environmental Science International
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• v.13 no.6
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• pp.581-589
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• 2004

This paper describes the amount of food consumption and the change of total weight of abalone under a vibration with noise that can be occurred due to piling work. This experiment was conducted in the aquarium in Yosu National University. In normal situation the juvenile stage shell's(total length is 1～1.5cm) amount of food consumption was 0.81g, the middle stage shell(total length is 3～3.5cm) was 13.61g, and the adult stage shell (Total length is 7～7.5cm) was 43.l9g per 5 organisms in 24 hours, while the experimental group was observed low numerical value compared normal groups. The abalones' food consumption and total weight in both groups, the intermittent and continuance impact with noise and vibration, was reduced during this experiment. The abalones' food consumption and total weight in the experimental groups without vibration were recorded slightly high numerical value than the experimental groups with noise and vibration. Based on this experimental data we could conjecture the noise and vibration are harmful factors to bring up a physiological stress to abalones. Especially, the vibration impact by piling works could produce a considerably unfavorable effect to the abalones than noise impact.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.3
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• pp.232-238
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• 2010

The moving ranges and behavior of four wild abalones, Haliotis discus hannai, were measured by an acoustic telemetry technique. The shape of the sea bottom of the experimental area was surveyed by a bathymetry system and three self-recording type acoustic receivers were used for monitoring the behavior and measuring the movement range. The abalones (WA1-WA4) attached acoustic tags were released and measured the movement during ten months. Three abalones (WA1, WA3 and WA4) were successively detected around the released point during the experiment and were moved to the V2 area where water depth is deeper than the V1 area. The change of inhabitation depth was also detected from the depth sensor of WA4. As the result, abalones were moved to deeper water area accordance with the decrease of the water temperature. The moved ranges of abalones were approximately 200 - 400m from the release point.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.410-412
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• 1983

On maturation of abalone KIKUCHI'S concept of accumulative temperature expressed ${\Sigma}(t_i-{\theta})$ have been apply importantly for an anniversary spawning of the animals. In case of Haliotis discus hannai he was formulated ${\Sigma}(t_i-7.6)>1300$. This expression is able to modify by UKI'S the relationship between the daily feeding rate ($\%$) (Y) ana temperature ($^{\circ}C$) (t) expressed Y= 0.4291 t-0.1501. The modified expression is as the formula ${\Sigma}(Y-3.05)>570$. And the concept its meaning involves is replaced with accumulative ingestion instead of accumulative temperature. This modified concept is understood that on maturation of abalone temperature decide on satiation level, food ingestion decide on gonad maturity rate.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.73-73
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• 2003

This study was carried out to evaluate the utilization of fermented skipjack tuna viscera (FSTV) in the diet for juvenile abalone Haliotis discus hannai. Lactobacillus bulgaricus was used for fermentation of skipjack tuna viscera. Eight isonitrogenous (about 30% crude protein) diets were formulated to include different levels (0%, 10%, 20% and 30%) of FSTV as a replacer of either dietary fish meal or soybean meal. Three replicate groups of abalone were fed the experimental diets containing different levels of FSTV for 7 weeks. The inclusion of FSTV up to 30% in fish meal-based diet had no significant effect on survival, body weight, shell growth, and proximate composition of abalone (P>0.05). Weight gain of abalone fed the diet substituting 10% FSTV for soybean meal was not significantly different to that of abalone fed the control diet, however this value decreased in abalone fed the 20% and 30% FSTV (P<0.05).The contents of crude protein and lipid of soft body in abalone fed soybean meal-based diets were significantly affected by dietary FSTV level (P<0.05). The results of this study indicate that FSTV can be used as a partial substitute protein source for fish meal or soybean meal in the formulated diet for juvenile abalone.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.121-130
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• 2008

In other aquaculture species, large improvements in growth have been achieved through selective breeding. Ezo abalone(Haliotis discus hannai) and disk abalone(H. discus discus) are major aquatic animals cultured in Asia, but selective breeding for the promotion of growth with these abalones has not been actively pursued. Recently significant efforts are being made to promote production of these species through selective breeding in Korea. The aims of this work were to estimate the general genetic parameters, heritabilities, and genetic and phenotypic correlations on growth-related traits at 1-year old in two Korean abalone subspecies, H. discus hannai and H. discus discus, by using multiple trait animal model. The data were collected from the records of 1,504 individuals produced from 22 sires and 26 dams in H. discus hannai and 297 individuals produced from 5 sires and 6 dams in H. discus discus, which evaluated by the Genetics and Breeding Research Center, National Fisheries Research & Development Institute(NFRDI). Genetic parameters were estimated for these abalone subspecies raised in Bukjeju branch, NFRDI, from May 20, 2004 to May 16, 2005, respectively. The heritability estimates obtained from restricted maximum likelihood(REML) were higher than expected, ranging from 0.40 to 0.43 for growth traits shell length, shell width and body weight in H. discus hannai and from 0.26 to 0.51 in H. discus discus, respectively. The heritabilities for shell shape and condition factor were lower than others of growth traits such as ranging from 0.09 to 0.19 in H. discus hannai and from 0.10 to 0.23 in H. discus discus, respectively. Genetic and phenotypic were > 0.93 between shell parameters and weight in two abalone species, respectively, indicating that breeding for weight gains could be successfully achieved by selecting for shell length.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.452-457
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• 2008

This study analyzed the proximate compositions, total amino acids, and fatty acid compositions in muscle and viscera of 51-month-old triploid and diploid Pacific abalone, Haliotis discus hannai. Proximate composition analysis showed that the muscle of diploid abalones had a higher protein and ash ratio than that of triploid abalones, while there was no significant difference in the ratios of moisture and fat (P>0.05). The triploid abalones had a significantly higher ratio of carbohydrate in muscle than the diploid abalones (P<0.05), which suggests that the transference of carbohydrates from muscle to gonad is decreased in sterile triploid organisms. Amino-acid analysis indicated that the total content was 133.42 mg/g in diploid muscle and 151.46 mg/g in triploid muscle. Taurine, arginine, glutamine, glycine, glutamic acid, alanine, and leucine, which are the major amino acids in abalone, were measured as 84.64 mg/g in triploid muscle and as 73.92 mg/g in diploid muscle. The essential amino acid content of triploid muscle (38.83 mg/g) was significantly higher than that of diploid muscle (31.94 mg/g) (P<0.05). Saturated fatty acids and monoene fatty acids were abundant in triploid muscle and polyene fatty acids were abundant in diploid muscle. Therefore, triploid Pacific abalone appears to be a good nutritional food source.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.280-291
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• 2019

Potential utility of 14 candidate housekeeping genes as normalization reference for RT-qPCR analysis with developmental samples (fertilized eggs to late veliger larvae) in Pacific abalone Haliotis discus hannai was evaluated using four different statistical algorithms (geNorm, NormFinder, BestKeeper and comparative ΔCT method). Different algorithms identified different genes as the best candidates, and geometric mean-based final ranking from the most to the least stable expression was as follow: RPL5, RPL4, RPS18, RPL8, RPL7, UBE2, RPL7A, GAPDH, RPL36, PPIB, EF1A, ACTB and B-TU. The findings were further validated via relative quantification of metallothionein (MT) transcripts using the stable and unstable reference genes, and expression levels of MT were greatly influenced according to the choice of reference genes. In overall, our data suggest that RPL5 and RPS18, either singly or in combination, are appropriate for normalizing gene expression in developmental samples of this abalone species, whereas ACTB, B-TU and EF1A are less stable and not recommended. In addition, our findings propose that standard deviations in geometric ranking as well as geometric mean itself should also be taken into account for the final selection of reference gene(s). This study could be a useful basis to facilitate the generation of accurate and reliable RT-qPCR data with developmental samples in this abalone species.